sandboxed-api/contrib/libidn2/libidn2_sapi.cc

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// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "libidn2_sapi.h" // NOLINT(build/include)
#include <cstdlib>
#include <fstream>
#include <iostream>
#include "absl/log/log.h"
#include "sandboxed_api/util/fileops.h"
static constexpr std::size_t kMaxDomainNameLength = 256;
static constexpr int kMinPossibleKnownError = -10000;
absl::StatusOr<std::string> IDN2Lib::ProcessErrors(
const absl::StatusOr<int>& untrusted_res, sapi::v::GenericPtr& ptr) {
SAPI_RETURN_IF_ERROR(untrusted_res.status());
int res = untrusted_res.value();
if (res < 0) {
if (res == IDN2_MALLOC) {
return absl::ResourceExhaustedError("malloc() failed in libidn2");
}
if (res > kMinPossibleKnownError) {
return absl::InvalidArgumentError(idn2_strerror(res));
}
return absl::InvalidArgumentError("Unexpected error");
}
sapi::v::RemotePtr p(reinterpret_cast<void*>(ptr.GetValue()));
auto maybe_untrusted_name = sandbox_->GetCString(p, kMaxDomainNameLength);
SAPI_RETURN_IF_ERROR(sandbox_->Free(&p));
if (!maybe_untrusted_name.ok()) {
return maybe_untrusted_name.status();
}
// FIXME: sanitize the result by checking that the return value is
// valid ASCII (for a-labels) or UTF-8 (for u-labels) and doesn't
// contain potentially malicious characters.
return *maybe_untrusted_name;
}
absl::StatusOr<std::string> IDN2Lib::idn2_register_u8(const char* ulabel,
const char* alabel) {
std::optional<sapi::v::ConstCStr> alabel_ptr;
std::optional<sapi::v::ConstCStr> ulabel_ptr;
if (ulabel) {
ulabel_ptr.emplace(ulabel);
}
if (alabel) {
alabel_ptr.emplace(alabel);
}
sapi::v::GenericPtr ptr;
sapi::v::NullPtr null_ptr;
const auto untrusted_res = api_.idn2_register_u8(
ulabel ? ulabel_ptr->PtrBefore() : &null_ptr,
alabel ? alabel_ptr->PtrBefore() : &null_ptr, ptr.PtrAfter(),
IDN2_NFC_INPUT | IDN2_NONTRANSITIONAL);
return this->ProcessErrors(untrusted_res, ptr);
}
absl::StatusOr<std::string> IDN2Lib::SapiGeneric(
const char* data,
absl::StatusOr<int> (IDN2Api::*cb)(sapi::v::Ptr* input,
sapi::v::Ptr* output, int flags)) {
sapi::v::ConstCStr src(data);
sapi::v::GenericPtr ptr;
absl::StatusOr<int> untrusted_res = ((api_).*(cb))(
src.PtrBefore(), ptr.PtrAfter(), IDN2_NFC_INPUT | IDN2_NONTRANSITIONAL);
return this->ProcessErrors(untrusted_res, ptr);
}
absl::StatusOr<std::string> IDN2Lib::idn2_to_unicode_8z8z(const char* data) {
return IDN2Lib::SapiGeneric(data, &IDN2Api::idn2_to_unicode_8z8z);
}
absl::StatusOr<std::string> IDN2Lib::idn2_to_ascii_8z(const char* data) {
return IDN2Lib::SapiGeneric(data, &IDN2Api::idn2_to_ascii_8z);
}
absl::StatusOr<std::string> IDN2Lib::idn2_lookup_u8(const char* data) {
return IDN2Lib::SapiGeneric(data, &IDN2Api::idn2_lookup_u8);
}